The hand grenade, in its generally known form, was invented in the 15th Century and has been widely used in warfare since the 17th Century. The present day form and structure of such devices have been basically unchanged since that time.
That specific prior art known to the inventor consists of United States Statutory Invention Registration No. H215 to Stewart, entitled Fuze for Riot Control Grenade; United Kingdom Patent No. 133,347 (1919) to Rushen; United Kingdom Patent No. 1,149,039 (1969) to Aktiebolag; and French Patent No. 2,528,967 (1982) to Chevallier.
The above, and other prior art known to the inventor, does not disclose a fragmentation device having an exterior surface capable of imparting a sufficient "bounce" or resilience to the device to permit the device to be rebounded off of flat surfaces to thereby reach a target which is not within a line of sight of the user of the device.
The utility of such device is particularly great in the area of urban combat in which combatants are rarely within a line of sight of each other and are, of course, reluctant to expose themselves to a possible line of sight of an enemy.